The system makes sense but it feels like there is probably a more intuitive easy to express those than with numbers. Naming is hard, of course, but off the top of my head maybe something like
I didn't down vote you, and your question deserves a serious reply because the same principle is broadly useful.
Communication is hard. People actively in the team probably have the context to understand the differences, but that implied context is what tribal knowledge is made of.
OP indicated that there were non-trivial "non-linear" differences going from 1 to 2 and -1 to -2. The use of numbers implies a relationship that doesn't really exist. The use of accurate language makes the actual meaning immediately obvious without the need for implied context. For example, I had no idea that only privileged devs could give 2s. "Accepted" and "Declined" do imply a finality that more accurately mirrors the intended usage.
This may seem overly analytical for something that is easy to just explain, but this kind of thing build up in layers.
-1: Changes Requested
-2: Declined
1: Approved
2: Accepted